The use of opioid medications to treat chronic non-cancer pain has increased markedly in recent years. However, it is unclear to what extent the use of opioids beyond acute care improves patient outcomes and which patients are most likely to benefit from opioids. The use of opioid medications in older adults has similarly increased, but there is very little empiric information available regarding the effectiveness of opioids for pain n older adults. In addition, older adults may be at greater risk for side effects and adverse events related to prescription opioids. The Department of Veterans Affairs (VA) collects pain intensity information as part of routine care; all patients are administered brief pain intensity measures at almost all outpatient visits. National level data including pain intensity scores and pharmacy information are stored in central VA administrative databases. This project responds directly to RFA-AG-12-006, Leveraging Existing Data or Longitudinal Studies to Evaluate Safety and Effectiveness of Pharmacological Management of Chronic Pain in Older Adults (R03), and takes advantage of a unique set of longitudinal data on pain intensity and prescription opioid use available to the researchers from national VA databases. This project extends the research teams' ongoing work examining pain-related outcomes and opioid prescribing patterns to further our understanding of opioid treatment outcomes among older adults. The specific objective of this study is to determine to what extent prescription opioids are associated with improvements in pain intensity among older adults treated in the VA healthcare system. Using a retrospective cohort design, we will examine a national sample of Veterans ages 65 years and older, who received VA care in 2010, who had moderate or greater pain intensity levels, and who had not been prescribed opioids in the prior 12 months. A subgroup of Veterans with new opioid starts will be examined for 12 months following opioid initiation. Most data will be obtained from the national VA Corporate Data Warehouse. We will conduct survival analysis using Cox regression models to identify factors associated with the main outcome, time to improvement in Numeric Rating Scale (NRS) pain intensity score. We will identify patient, medication-related, and site factors that predict time to improvement, including patient demographics and documented clinical diagnoses, opioid medication dose and frequency of use, and VA facility type and geographic region. Propensity scores will be used to adjust for measurable characteristics associated with opioid initiations, and in a secondary analysis, we will use geographic region as an instrumental variable to adjust for relationships between unmeasured disease severity and opioid initiations. Findings from this study will provide important information about the impact of prescription opioids on pain treatment outcomes in older adults. Results will be of considerable interest to Veterans, older adults with pain, and clinicians who treat chronic pain.